I have a problem. My pick rotates on me. I usually play in a "root-strum" fashion - very easy, comfortable and unchallenging. No problem holding onto the pick there. But whenever I start to do a "down-up" rhythm pattern, the pick slips. More accurately, it rotates clockwise. At some point I have to pause and re-grip it. If I try to hold it more tightly to prevent it from slipping, it sounds like I'm dragging or scraping it across the strings and sounds awful.
One thing I've recently discovered is that when the pick is slippery... that means my finger and thumb are too oily. Washing my hands helps. If I don't wash my hands, I take an alcohol swab... rub it between my thumb and finger, then wipe off the pick as well. Works wonders!!!
I've also used a 1/16" drill bit to drill some small holes in the pick. Rubbing the pick with sandpaper works good.
I have the opposite problem as well.... wanting a pick that's MORE slippery. I love Tortex picks because they feel great grip wise... but they drag too much on the strings. And I don't think they sound as good as celluloid once you get to the 1.0 blue Tortex. .88 green sounds good though.
So that's what's going on with my hand - trigger finger? For a number of weeks when I open my hand in the morning my fingers - mainly the middle one - resist opening and suddenly - pop! It feels looser as the day goes on but is closely related to how long I practiced the day before. I'll get some Coban and see if it helps both problems.